Heat-treating metal



July 6, 1937. v J. J. BOWDEN HEAT TREATING METAL Filed Sept. 18; 19:55

2 Sheets-Sheet l INVENTOR.

/M' MM ATTORNEY.

July 6, 1937. J; J. BOWDEN HEAT TREATING METAL Filed Sept. 18, 1935 2 Sheets-Sheet 2 v INVENTOR. I J 760 MHZ n h ve: M

I ATTORNEY.

Patented July 6, 1937 UNITE TATES PATENT HEAT-TREATING IVIETAL James J. Bowden, Warren, Ohio Application September 18, 1935, Serial No. 41,102

2 Claims.

This invention relates to a method of heat treating metal and is an improvement on the invention disclosed inmy prior Patent No. 1,824,865, patented September 29, 1931, and a continuation 5 in part of my copending application Serial No.

735,257, filed July 14, 1934.

An object of the invention is to provide for attaining all the advantages of my previous patent and without the necessity of completely or even substantially submerging the receptacle in the molten salt or similar fusion. The principal object is to provide for an increase in the efficiency of combustion heater or heaters to be placed within an enclosed space into which a re- 15 ceptacle containing metal to be treated is to be placed by'reason of the fact that such heater is not permitted to drop to a low temperature when the charge is being changed. A further object is to dampen or even the heat exchange from the heater to the charge so that there is no danger of overheating adjacent parts and underheating more remote ones. A still further object (of one form of the invention) is to avoid all direct contact of the liquid, if liquid be used as the heat absorbing and transferring medium, with the vessel containing the charge.

Other and more limited objects will become apparent from the following description especially when read in connection with the accompanying 30 drawings wherein Fig. 1 is a vertical section taken through a modified form of exterior construction, the charge container being optionally, any form shown; Fig. 2 is a plan section of the modification of Fig. 1; Fig. 3 is a further modified form of outer construction which may be used without any inner container; and Fig. is a plan section of the form shown in Fig. 3.

The apparatus which I prefer to employ in carrying out my improved process of heat treatment will be first described, after which the process itself will be outlined in connection with the operation of the apparatus.

In Figs. 1 and 2, I have shown an embodiment of the invention wherein heat transferring, evening and storing means is held out of contact with the charge containing receptacle. In these views, which are more or less diagrammatic, the outer receptacle construction is indlcated by the numeral 50. Adjacent the inner lining 6| thereof, I position a plurality of combustion type heaters 62, each of which may consist of a U-shaped tubular portion, bent if desired to conform to bottom and side walls. At one end of each is a fuel feed tube 53 through which may be fed in a proper mixture a combustible gas and air. Products of combustion may escape at the other end. Other types of combustion heaters, capable of being submerged, or closely surrounded by air excluding media, may be employed. 5 Within the lining 6i and supported by transverse members 64 or other suitable means is aninner receptacle 65. Between the receptacle members 6! and 65 are the heaters 62 and a heat absorbing evening and transferring medium 66 which 10 may take the form of lead or other fusible metal or substance. Preferably such substance closely surrounds the heaters so that the temperature of the latter cannot drop very much when the charge is changed A lid Bl may be provided for covering the receptacle $0. The cradle 68 and charge containing receptacle 59 may be of any. suitable construction, preferably such as to enclose the charge substantially completely and provide for handling of the container and the charge by suitable lifting machinery.

In Figs. 3 and 4, I have shown a form of my invention in which the charge is supported with or without an enclosing receptacle on a base ill, on the upper surface ll thereof. A downwardly opening receptacular element 72 is is adapted to cover the charge on the surface ii. Suitable heaters l3 of the combustion type may extend through the walls of the element 72 and back again for discharge of products of combustion. As many of these as desired may be supplied through tubes 14 from a manifold 55 supplied by a pipe 15a. On the inner wall of the element l2 may be supported in any suitable manner a containing means it, or a plurality thereof, adapted to hold a heat absorbing and transferring medium ll adapted to surround the heaters it. At the upper part, the element 12 may be provided with any suitable lifting means 18 for moving it bodily to and from a position in covering relation to a charge resting on the surface ll.

In the forms of the invention shown excellent results are attained without actual contact of any liquid with the receptacle, if any is used, containing the charge, and much better results than if the heaters were merely placed adjacent the charge and separated therefrom by an air or gas medium merely.

While I have disclosed preferred embodiments of my invention I wish it understood that the same is not limited to the details of the disclosure but only in accordance with the spirit and scope of the appended claims and the prior art.

- claim is:

1. In combination, in a device for heat treating metal. an outer receptacle, means including an inner receptacle for supporting a charge of metal to be treated therewithin and in spaced relation thereto, combustion heating means within said outer receptacle and between the same and said charge, and a non-gaseous heat absorbing and transferring means surrounding said heating means and means for maintaining said heat absorbing and transferring means out of contact with the charge to be treated and the said inner receptacle.

2. In combination in a device for heat treating metal. an outer receptacle, means for supmeans.

JAMES J. BOWDEN. 

